無法編譯Kotlin代碼

-2

我想實現用kotlin編寫的Facebook登錄。下面的代碼工作正常：無法編譯Kotlin代碼

包social.social

import android.content.Intent 
import android.support.v7.app.AppCompatActivity 
import android.os.Bundle 
import com.facebook.* 
import com.facebook.login.LoginResult 
import com.facebook.login.LoginManager 
import com.facebook.login.widget.LoginButton 
import org.json.JSONObject 
import java.util.* 


class MainActivity : AppCompatActivity() { 
    private var callbackManager: CallbackManager? = null 

    override fun onCreate(savedInstanceState: Bundle?) { 
     super.onCreate(savedInstanceState) 
     setContentView(R.layout.activity_main) 

     callbackManager = CallbackManager.Factory.create() 
     var loginBtn: LoginButton = findViewById(R.id.login_button) as LoginButton 
     loginBtn.setReadPermissions(Arrays.asList("public_profile","email","user_photos")) 
     loginBtn.registerCallback(callbackManager, object : FacebookCallback<LoginResult> { 
      override fun onCancel() { 
       TODO("not implemented") //To change body of created functions use File | Settings | File Templates. 
      } 


      override fun onError(error: FacebookException) { 
       print("error" +error.message) 
      } 

      override fun onSuccess(result: LoginResult) { 
       GraphRequest.newMeRequest(result.accessToken, GraphRequest.GraphJSONObjectCallback { 
        obj: JSONObject, response: GraphResponse -> 
        println(obj.toString()) 
        println(obj.getString("email"))}) 
       println("successful" + result.accessToken) 
      } 
     }) 
    } 



    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) { 
     super.onActivityResult(requestCode, resultCode, data) 
     callbackManager!!.onActivityResult(requestCode, resultCode, data) 
    } 

}

我嘗試添加參數GraphRequest所以我需要將它存儲到一個變量，像這樣：

val request: GraphRequest = GraphRequest.newMeRequest(result.accessToken, GraphRequest.GraphJSONObjectCallback { 
        obj: JSONObject, response: GraphResponse -> 
        println(obj.toString()) 
        println(obj.getString("email"))}) 
       request.executeAsync()

但現在它編譯失敗

錯誤：執行任務'：app：compileDebugJavaWithJavac'失敗。